Virgin native Olive oilDecember 2008, Rio Seco, Almuñécar(Granada). Olive harvest with friends, production of Olive oil. The way of making olive oil is by grinding olives. Green olives produce bitter oil, and overripe olives produce rancid oil, so care is taken to make sure the olives are perfectly ripened. First the olives are ground into paste. The olive paste generally stays in the mill for 30-40 minutes. The oil collected during this part of the process is called virgin oil. After grinding, the olive paste is spread on fibre disks, which are stacked on top of each other, then placed into the press. Modern factories use centrifuges. Best quality is by cold pressing(30° cel.).